ELISA or of you like, the Enzyme Linked Immunosorbent Assays are the most prevalent biochemical tests used to determine the presence of proteins as antigens or antibodies in substrates. There are four main types of ELISA tests. These include direct, indirect, sandwich and competitive ELISA tests. The results obtained from ELISA tests are considered to be very accurate because of the precision, conciseness, repetitiveness, and the ability to determine very low concentrations of proteins. ELISA uses colorimetric readings to ascertain the accuracy, presence or absence of the molecule being tested. As a result of the accuracy, economical nature, and the effectiveness of the tests, ELISA tests are used in the following application areas:
1. Determination of Antibody Concentrations
To determine the levels of a particular antibody indicative of a disease in blood serum, the indirect ELISA test is run. The amount of antibodies present in the serum or the fluid sample is shown by the spectrophotometric readings given. High readings shown by deeper colors indicate a high level of antibodies in the tested fluid sample.
2. Home Pregnancy Tests
There are two types of pregnancy tests; urine and blood tests. The tests determine the presence and the levels of human chorionic gonadotropin (HCG). HCG is produced immediately after the ovum is fertilized and the normal HCG levels in blood spike two or even three times when you are pregnant. Blood pregnancy tests are qualitative and quantitative. ELISA measures HCG levels. In the home pregnancy kit, the sandwich ELISA test is used to measure the levels of HCG and the color changes used to show if you are pregnant or not. The visual comparison between the intensity of the blue color given against the positive control indicates if one is pregnant or not.
3. Screening for Monoclonal Antibodies
Monoclonal antibodies refer to antibodies made by similar immune cells that are clones of the parent cells. These parent cells are unique and the monoclonal antibodies therefore have a monovalent affinity by binding to similar unique epitopes. The MBS testing kits are used in screening for monoclonal antibodies. The latter have been used effectively to create monoclonal antibody drugs used in cancer therapy.
4. ELISA Testing for Viruses
Viruses and viral diseases incorporate the ELISA test. ELISA has been applied widely in testing the HIV virus because of its accuracy in determining if the sample fluid is infected by the virus or not. The accuracy of the test has also made the test appropriate for testing the West Nile Virus in the cerebrospinal fluid or for the Newcastle Disease Virus that causes respiratory problems, diarrhea, and eventually death. These test results faster and are therefore preferable and effective in case of human or animal disease breakouts. Ebola, Zika Virus etc. have all been tested using ELISA.
5. Food Tests
Most food allergies cause anaphylaxis that causes almost immediate death if not reversed. The big eight allergens tested often include peanuts, wheat, tree nuts, soy, eggs, milk, fish, and shellfish. These tests are also done in product testing to keep users safe.
In conclusion, the accuracy, precision, sensitivity, and the ability to reproduce results all the time make it one of the most reliable biochemical test.